Exercise equipment, such as treadmills, is widely used in spas, exercise clubs, and in individual residences to enable users to walk, jog, or run indoors. This is especially useful during inclement weather and also at night or at other times when exercisers do not desire to run outdoors. Structurally, most exercise treadmills include first and second roller assemblies that are transversely mounted at the ends of an essentially rectangular frame. An endless belt is entrained about the roller assemblies. The upper run of the belt is supported by an underlying deck positioned between the belt and the frame.
Known treadmills include a number of disadvantages relating to their assembly. For example, some treadmill manufacturers bolt the rear of the deck to the frame, in effect, creating a diving-board configuration. This increases the stresses in the deck and results in a stiff feel to the user. Thus, it is desirable to include components in a treadmill that allow the rear of the deck to deflect in response to the steps taken by the user on the treadmill belt. Known deflection systems include a short aluminum pivot pin welded onto the rear inner surface of each side rail. The pins extend inwardly a short distance. A small upright plate is bolted to the rear underside surface of the deck at each corner and extends downwardly therefrom in a longitudinal orientation. The plate includes a circular opening at its center. As assembled, the pivot pin is held in the circular opening, thus allowing the deck to pivot relative to the frame. The above system, however, is costly to manufacture, has many parts that require maintenance, and does not have a streamlined appearance.
It is also known to include rear elevation adjustment components on the frame in order to even out the elevation of each rear corner of the treadmill. In one known system, a relatively flat rear foot is attached to a bolt that is insertable in a nut located on the underside of the frame. To raise and lower the foot, the user must use a wrench to manually adjust each column relative to its corresponding nut. This requires the user to assume a physically awkward position and to locate the nut, which is visually hard to see.
Further, it is known to use a standard poly-V belt (i.e., a belt profile that contains multiple V grooves) in driving the roller assemblies from the motor. The material used in a standard V belt is often nylon or a low-stretch polyester tensile cord. Low-stretch belts are applied with the center-to-center distance between the motor drive pulley and the front axle being less than is needed during use. This allows the installer to place a slack belt around both components. The drive pulley and front roller pulley are then pushed apart while the belt tension is monitored. Once the desired belt tension is achieved, the motor is secured in place. Because these standard belts have a low stretch capability, any small variation in the center-to-center distance results in a large variation in the belt tension. It is not infrequent that such standard belts are installed with an unnecessary overtension. Overtensioning a drivebelt is undesirable as it can be a factor in creating early bearing failure in motors.
Another problem with known treadmill assemblies is the tendency for debris to pass between the endless belt and the motor compartment. Such debris can interfere with the workings of the motor compartment components and/or the endless belt. Lastly, the frames of treadmills are currently made using welds or bolts between frame elements. Disadvantages of using welds include that they are time consuming to accomplish; they can affect the minimum configurable size of the subassemblies; and they can decrease the efficiency in painting and prepping the frame. Likewise, using bolts also has disadvantages. Because the frame is under random vibration loads, conventional bolts will require retorquing after a period of time to ensure a solid working joint.
Thus, there are multiple needs for improvement to known treadmill assemblies. An ideal machine would allow for efficient rear pivoting of the deck, an easy method of raising and lowering the frame's rear elevation, an easy method of assembling the drivebelt between the motor assembly and roller assembly, a reduction in the transference of debris between the motor compartment and the deck belt, and an improved connection between the frame's structural elements. The present invention is directed to fulfilling such needs and others, as described below.